(45 days)
Internal fixation implants are load-sharing devices intended to stabilize and maintain alignment until normal healing occurs. Implants are not intended to replace normal body structures or bear the weight of the body in the presence of incomplete bone healing.
The NAUTILUS Spinal System, when properly used, is intended for posterior pedicle screw fixation of the non-cervical posterior spine in skeletally mature patients. It provides stabilization and immobilization of spinal segments as an adjunct to fusion.
When used as a posterior spine thoracic/lumbar system, the NAUTILUS Spinal System is indicated for one or more of the following: (1) degenerative disc disease (is defined as back pain of discogenic origin with degeneration of the disc confirmed by history and radiographic studies), (2) trauma (i.e. fracture or dislocation), (3) curvatures (scoliosis, and/or lordosis), (4) spinal tumor, (5) failed previous fusion (6) pseudarthrosis, (7) spinal stenosis, (8) spondylolisthesis.
The NAUTILUS Thoracolumbar Spinal System consists of an assortment of rods, screws, cross connectors, and axial and offset connectors. The bone screw, head, and taper lock are assembled together during manufacturing to create the NAUTILUS Thoracolumbar Spinal System screw assembly component. The cross, axial, and offset connectors are also assembled during manufacturing. The NAUTILUS Thoracolumbar Spinal System implant components are made from titanium alloy (Ti-6A1-4V ELI) as described by ASTM F136. Do not use any of the NAUTILUS Thoracolumbar Spinal System components with the components from any other system or manufacturer.
This 510(k) summary for the NAUTILUS Spinal System describes a medical device and its substantial equivalence to predicate devices, rather than a study evaluating device performance against pre-defined acceptance criteria in terms of accuracy or clinical outcomes. The provided document is for a pedicle screw spinal system, which is a physical implant, not an AI/ML-driven diagnostic or prognostic device that typically involves performance metrics like sensitivity, specificity, or AUC.
Therefore, many of the requested categories for AI/ML device evaluation (like sample size for test/training sets, ground truth establishment by experts, adjudication methods, MRMC studies, standalone performance) are not applicable to this type of submission.
However, I can extract the relevant information regarding the performance data that was provided to demonstrate substantial equivalence for this physical device.
Acceptance Criteria and Study for NAUTILUS Spinal System
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Specific Criteria/Test | Reported Device Performance |
|---|---|---|
| Mechanical Performance | Dynamic Compression | Demonstrated substantial equivalency to predicate devices. (Details on specific force/displacement values or cycle counts are not provided in this summary, only the statement of equivalency.) |
| Material Composition | ASTM F136 compliant | Made from titanium alloy (Ti-6A1-4V ELI) as described by ASTM F136. |
| Indications for Use | Match Predicate Devices | Substantially equivalent to predicate systems in terms of indications for use. |
| Design | Match Predicate Devices | Substantially equivalent to predicate systems in terms of design. |
| Sizing | Match Predicate Devices | Substantially equivalent to predicate systems in terms of sizing. |
Explanation: For a traditional medical device like a spinal system, "acceptance criteria" primarily relate to engineering and material standards, as well as functional performance benchmarks established by recognized industry standards (e.g., ASTM). The "study" here refers to bench-top testing.
2. Sample Size used for the test set and the data provenance
- Sample Size (Test Set): Not explicitly stated as "sample size" in the context of clinical data. For bench-top mechanical testing, the "samples" would be the physical implants tested. The number of such implants tested is not specified in this summary.
- Data Provenance: N/A. Bench-top mechanical testing is performed in a laboratory setting. There is no patient data involved for this type of submission focused on substantial equivalence of a physical implant.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- N/A. This information is not relevant to the evaluation of a physical implant's mechanical properties. Ground truth, in the context of AI/ML, refers to a definitive correct answer for a diagnostic or prognostic task, typically established by clinical experts.
4. Adjudication method for the test set
- N/A. Adjudication methods are used in clinical studies or expert reviews to resolve disagreements in ground truth labeling for AI/ML models. This is not applicable to a submission focusing on the mechanical equivalence of a spinal implant.
5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
- N/A. MRMC studies are used to evaluate the impact of AI on human readers' performance in diagnostic tasks. This device is a surgical implant, not an AI diagnostic tool.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- N/A. Standalone performance evaluation is for AI algorithms. This is a physical device.
7. The type of ground truth used
- Mechanical & Material Standards: For this device, the "ground truth" (or objective standard) for its performance is adherence to established engineering standards (e.g., ASTM F1717 for dynamic compression testing) and material specifications (e.g., ASTM F136 for titanium alloy). The comparison is against these standards and the performance of the predicate devices.
8. The sample size for the training set
- N/A. There is no "training set" in the context of a physical medical device's mechanical performance evaluation. Training sets are for AI/ML model development.
9. How the ground truth for the training set was established
- N/A. As there is no training set for this type of device submission, this question is not applicable.
§ 888.3070 Thoracolumbosacral pedicle screw system.
(a)
Identification. (1) Rigid pedicle screw systems are comprised of multiple components, made from a variety of materials that allow the surgeon to build an implant system to fit the patient's anatomical and physiological requirements. Such a spinal implant assembly consists of a combination of screws, longitudinal members (e.g., plates, rods including dual diameter rods, plate/rod combinations), transverse or cross connectors, and interconnection mechanisms (e.g., rod-to-rod connectors, offset connectors).(2) Semi-rigid systems are defined as systems that contain one or more of the following features (including but not limited to): Non-uniform longitudinal elements, or features that allow more motion or flexibility compared to rigid systems.
(b)
Classification. (1) Class II (special controls), when intended to provide immobilization and stabilization of spinal segments in skeletally mature patients as an adjunct to fusion in the treatment of the following acute and chronic instabilities or deformities of the thoracic, lumbar, and sacral spine: severe spondylolisthesis (grades 3 and 4) of the L5-S1 vertebra; degenerative spondylolisthesis with objective evidence of neurologic impairment; fracture; dislocation; scoliosis; kyphosis; spinal tumor; and failed previous fusion (pseudarthrosis). These pedicle screw spinal systems must comply with the following special controls:(i) Compliance with material standards;
(ii) Compliance with mechanical testing standards;
(iii) Compliance with biocompatibility standards; and
(iv) Labeling that contains these two statements in addition to other appropriate labeling information:
“Warning: The safety and effectiveness of pedicle screw spinal systems have been established only for spinal conditions with significant mechanical instability or deformity requiring fusion with instrumentation. These conditions are significant mechanical instability or deformity of the thoracic, lumbar, and sacral spine secondary to severe spondylolisthesis (grades 3 and 4) of the L5-S1 vertebra, degenerative spondylolisthesis with objective evidence of neurologic impairment, fracture, dislocation, scoliosis, kyphosis, spinal tumor, and failed previous fusion (pseudarthrosis). The safety and effectiveness of these devices for any other conditions are unknown.”
“Precaution: The implantation of pedicle screw spinal systems should be performed only by experienced spinal surgeons with specific training in the use of this pedicle screw spinal system because this is a technically demanding procedure presenting a risk of serious injury to the patient.”
(2) Class II (special controls), when a rigid pedicle screw system is intended to provide immobilization and stabilization of spinal segments in the thoracic, lumbar, and sacral spine as an adjunct to fusion in the treatment of degenerative disc disease and spondylolisthesis other than either severe spondylolisthesis (grades 3 and 4) at L5-S1 or degenerative spondylolisthesis with objective evidence of neurologic impairment. These pedicle screw systems must comply with the following special controls:
(i) The design characteristics of the device, including engineering schematics, must ensure that the geometry and material composition are consistent with the intended use.
(ii) Non-clinical performance testing must demonstrate the mechanical function and durability of the implant.
(iii) Device components must be demonstrated to be biocompatible.
(iv) Validation testing must demonstrate the cleanliness and sterility of, or the ability to clean and sterilize, the device components and device-specific instruments.
(v) Labeling must include the following:
(A) A clear description of the technological features of the device including identification of device materials and the principles of device operation;
(B) Intended use and indications for use, including levels of fixation;
(C) Identification of magnetic resonance (MR) compatibility status;
(D) Cleaning and sterilization instructions for devices and instruments that are provided non-sterile to the end user; and
(E) Detailed instructions of each surgical step, including device removal.
(3) Class II (special controls), when a semi-rigid system is intended to provide immobilization and stabilization of spinal segments in the thoracic, lumbar, and sacral spine as an adjunct to fusion for any indication. In addition to complying with the special controls in paragraphs (b)(2)(i) through (v) of this section, these pedicle screw systems must comply with the following special controls:
(i) Demonstration that clinical performance characteristics of the device support the intended use of the product, including assessment of fusion compared to a clinically acceptable fusion rate.
(ii) Semi-rigid systems marketed prior to the effective date of this reclassification must submit an amendment to their previously cleared premarket notification (510(k)) demonstrating compliance with the special controls in paragraphs (b)(2)(i) through (v) and paragraph (b)(3)(i) of this section.